AU674660B2

AU674660B2 - Self-compensated and electrically heated reducer for compressed gas or L.P.G.

Info

Publication number: AU674660B2
Application number: AU24449/92A
Authority: AU
Inventors: Arturo Barbanti
Original assignee: BB Srl; B B Srl
Current assignee: B B Srl
Priority date: 1991-07-30
Filing date: 1992-07-22
Publication date: 1997-01-09
Anticipated expiration: 2012-07-22
Also published as: US5445134A; EP0526410A1; CA2114432A1; HU9400248D0; ITBO910290A0; DE69201765T2; EP0526410B1; AU2444992A; ITBO910290A1; BG98427A; JPH07503509A; BG61737B1; IT1252911B; DE69201765D1; BR9206401A; HUT67908A; WO1993003269A1; RU2091601C1

Description

OPI DATE 02/03/93 AOJP DATE 13/05/93 APPLN. ID 24449/92 1li il i PCT NUMBER PCT/IT92/00085 Illlll IlIil Iii illl ll I ii AtU,,e24449 INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT) (51) International Patent Classification 5 (11) International Publication Number: WO 93/03269 F02M 21/02, G05D 16/06 Al (43) International Publication Date: 18 February 1993 (18.02,93) (21) International Application Number: PCT, 1T92'00085 (81) Designated States: AU, BG, BR, CA, HU, JP, KR, RU,

US.

(22) International Filing Date: 22 July 1992 (22.07.92) Published Priority data: With international warch report.

B091A000290 30Jul\ 1991 (30.0".91) IT; (71) Applicant (for all designated States except US): B B S.R.L.

[IT/IT]; Via Oreste Regnoli, 23, 1-47100 Forli (IT).

(72) Inventor; and Inventor/Applicant (for US only; BARBANTI, Arturo [IT/ IT; Via del Lavoro, 81, 1-40033 Casalecchio di Reno

(IT).

(74) Agent: RINALDI, Carlo: Piazza di Porta Castiglione. 16, 1-40136 Bologna 2 674 (54)Title: SELF-COMPENSATED AND ELECTRICALLY HEATED REDUCER FOR COMPRESSED GAS OR L.P.G.

F F 3 4 I On 1"7 19 ti 4 27 36 34 28 29 31 32 33 (57) Abstract A self-compensating and electrically heated reducer for compressed gas or l.p.g. comprising, a supporting body a chamber formed inside the body a diaphragm an opening inlet between an entrance and the chamber a closing mechanism-(7) for an opening inlet controlling the flow rate of fuel owing to the action of manoeuvering elements (12, kinematically connected to the diaphragm on the device controlling the pressure of the fuel coming from the bottle; a mechanism (26, 30) which acts on at least one of the manoeuvering elements (12, 17) to cancel the resultant of the action of the pressure of the fuel on the mechanism electrical resistors (37) connected with the feeding system in the engine placed in thermic contact with the walls (38) of the body near the inlet SELF-COMPENSATING AND ELECTRICALLY HEATED REDUCER FOR COMPRESSED GAS OR L.P.G.

The present invention relates to a self-compensating electrically heated reducer for a feeding system of an internal combustion engine fed by a compressed fuel such as l.p.g. These combustible gases may be housed in bottles and employed for feeding internal combustion engines for motor transport or for stationary equipment.

Since the pressure of the gas housed in the bottle decreases progressively with its consumption from a value of several hundreds of bars to zero, the uncontrolled forces to which the lever in the pressure regulator is subjected vary from some hundreds of Newtons (or 10 N.x to zero. In the first case, the uncontrolled forces are equal to the forces which the lever receives from the controlling diaphragm of the flow rate and the outlet pressure of the gas; in the second case they are zero. The precise degree of adjustment is negatively affected to a marked degree by the progressively decreasing variation of these forces.

As a result of the lack of precise adjustment and particularly when the pressure of the S 15 gaseous fuel is high, irregularities occur in the idling speed of the motor, consumption is higher than usual, and there is an uncontrollable emission of pollutants.

The irregularities in the slow running of the engine, the increased consumption and emission of polluting gases are aggravated by the differences in the amount of heat, which in standard water heat exchangers installed in the traditional pressure reducers is transmitted to the outflowing fuel emitted in a gaseous state by the reducer.

US-A 1 450 236 discloses a pressure reducer. In a supporting body of said reducer a chamber is housed, 2 the chamber presents an entrance and an outlet which are respectively connected with a source of a compressed fluid and a device of use.

A compensating mechanism is capable of cancelling the momentum which results from the action of the gas pressure on a manoeuvring device which is controlled by a main diaphragm of the reducer, The manoeuvring device comprises a two-arm lever which pivots on a pivot fulcrum under the action both of a plunger, which acts the first arm and a spring which urges the second arm of the lever. In addition the lever is mechanically connected with the main diaphragm.

According to the axial movements of the main diaphragm, the lever rotates so that the plunger may close or open an opening inlet connected with the entrance. The movements of the lever are controlled by said spring, whose first end rests on a rigid plate which moves with an auxiliary diaphragm exposed to the pressure of gas via an auxiliary channel also connected with the entrance.

In this way the momentum due to the pressure forces which act the lever is cancelled.

The main disadvantage of the reducer disclosed in US-A 1 450 236 is the use of the spring and the auxiliary diaphragm. These mechanical elements may be subjected to damage and breaking due to the running of the vehicle.

In addition, the scattering of elastic peculiarities of mass-produced springs may enlarge 20 the dimensional tolerances so as to make production non economically acceptable because of manufacturing wastes.

3 Regarding the auxiliary diaphragm it is to be remembered that its mounting on the body may be difficult. In addition said diaphragm may be damaged after a certain time in service, because of the high values of the pressure which it is subjected to.

EP-A-O 182 952 discloses an electrically heated reducer for compressed gas or l.p.g.

having electrical resistors connected with the feeding system of the engine placed in contact with the walls of the reducer body.

Said resistors are housed in a notch of an inner wall of the reducer and maintained adherent to the lower surface of said wall by means of springs placed between the upper surface of resistors and the lower surface of a metal plate fixed to the upper surface of said wall.

The arrangement of the resistors disclosed in EP-A-0 182 952 is not capable of heating the fuel coming from the entrance of the reducer without an excessive consumption of electrical power, since to adequately heat the fuel it is necessary to heat all the wall and a good portion of the reducer body.

It is an object of this invention is to obviate these disadvantages.

The invention, as claimed, addresses the problem by creating a pressure reduction unit which is self-compensating and electrically heated for compressed gases or by means of which the resulting thrust or the consequent momentum arising from the thrusts on the regulation lever, due to the pressure of the fuel contained in the bottle, are reduced to zero 20 whatever the pressure, and the fuel which is emitted in a gaseous state from the reducer is heated to the same amount of heat per unit of mass of fuel supplied in every thermic state of the engine.

the engine.

*SS oSS

A

3a According to the present invention there is provided a self-compensating and electrically heated reducer for a feeding system of an internal combustion engine fed by a compressed fuel such as l.p.g. comprising: a supporting body; a chamber in the supporting body which is connected by a first channel in the supporting body to an inlet which is able to be connected to a container of the compressed fuel, whereby the chamber is fed with the compressed fuel, the chamber being also connected to an outlet which is able to be connected via other components of the feeding system to the internal combustion engine; a closing mechanism which opens and closes an inlet opening of the first channel which I opens onto the chamber, the closing mechanism thereby controlling rate of flow of fuel through the opening inlet to the chamber;

S

a diaphragm; manoeuvring elements mechanically connecting the diaphragm with the closing mechanism 15 whereby at each variation of internal pressure in the chamber in response to a vacuum caused by the internal combustion engine, the diaphragm acts via the manoeuvring elements on the closing mechanism to vary the rate of flow of fuel to the chamber to keep the internal pressure in the chamber substantially constant; a first thrusting mechanism which acts on at least one of the manoeuvring elements and which uses pressure of the compressed fuel to provide a cancelling thrust which cancels a thrust transmitted to the manoeuvring elements by the closing mechanism and resulting from pressure applied on the closing mechanism by fuel flowing through the inlet opening of the first channel; and electrical resistors, connectable to other elements of the feeding system, placed in thermic contact with walls of the body near the inlet opening of the first channel.

3b The reducer in one form has the manoeuvring elements comprising a first manoeuvring lever mounted in the supporting body for rotational movement about a pivot point and having first, second and third arms, the second arm being mechanically connected to the diaphragm so that the diaphragm can rotate the first manoeuvring lever; the closing mechanism for the inlet opening of the first channel comprises a second thrusting mechanism which has a first plunger for opening and closing the inlet opening of the first channel, the first plunger being engaged with one end of a first push rod which at the other end thereof engages the first arm of the manoeuvring lever, whereby pressure applied on the first plunger by the fuel passing through the inlet opening results in a thrust 10 on the first arm of the manoeuvring lever which acts on the first arm of the manoeuvring lever in a first direction; a second channel in the supporting body connects the inlet to the chamber; and the first thrusting mechanism comprises a second plunger located in the second channel, the second plunger being engaged with one end of a second push rod which at the other end engages the third arm of the manoeuvring lever, whereby pressure applied on the second plunger by fuel in the 15 second channel results in the cancelling thrust which is applied on the third arm of the manoeuvring lever and which acts to rotate the manoeuvring lever in a second sense opposite to the first sense and thereby negates the thrust on the first arm of the manoeuvring level.

4 The advantages of the present invention lie in the possibility of controlling the pressure and maintaining constant the temperature of the fuel which is fed by the pressure reducer for every value of the pressure of the fuel contained in the bottle. This is achieved by means of the diaphragm and of the specially placed electrical resistors in the regulator. In this way, the regular idling speed of the engine, a measured consumption of fuel and a limited and controlled emission of pollutants may be obtained.

In one possible embodiment of the present invention, there is provided a self-compensating and electrically heated reducer for compressed fuels such as l.p.g.

comprising, a supporting body, a chamber connected to an inlet, which is able to be connected to a container of compressed fuels such as 1.p.g. to feed the compressed fuel into the chamber, and an outlet, which is able to be connected to an internal combustion engine. It also comprises a diaphragm, which at each variation of the internal pressure of the chamber in response to the vacuum caused by the engine, acts on a closing mechanism of an inlet opening situated at the end of a first channel located between the inlet and the chamber and which by 15 the action of manoeuvring elements mechanically connected to the diaphragm keeps the internal pressure in the chamber substantially constant. There is also included electrical resistors, connected to the feeding system in the engine, placed in thermic contact with walls of the body to heat the fuel flowing along the first channel, wherein the electrical resistors are placed near the inlet opening.

Preferably there is included a thrusting mechanism which acts on at least one side of the manoeuvring elements to cancel the resultant of the action of pressure of the compressed fuels on the manoeuvring elements. The thrusting mechanism may comprise first and second thrusting mechanisms, the first thrusting mechanism comprising a push rod engageable at one thrusting mechanisms, the first thrusting mechanism comprising a push rod engageable at one end with a first plunger, and engageable at the other end with a first arm of the manoeuvring element. The first plunger comprises the closing mechanism which is situated at one end of the first plunger wherein the first plunger acts on the first arm by means of the thrusting action brought about by the pressure of the compressed fuels in the first channel. The second thrusting mechanism is located in a second channel positioned between the inlet and the chamber, the second thrusting mechanism engaging a third arm opposite the first arm with reference to a pivot point of the manoeuvring elements wherein the thrusting mechanism acts on the third arm to negate the momentum of the first plungers thrust on the first arm.

In a preferred embodiment the resistors present a resistivity which varies in inverse proportion to the temperature. The resistors are of type P.T.C.

In a preferred embodiment, the second channel is greater than the diameter of the first channel.

In another preferred embodiment the first channel is rectilinear, the second channel having a rectilinear part parallel with the first channel. The second thrusting mechanism may 15 comprise a second plunger housed in the rectilinear part of the second channel and a pusher fitted with a sliding housing in a cylindrical cavity, the second plunger and the pusher articulating the second thrusting mechanism.

In yet another preferred embodiment, the second arm includes an end which is mechanically connected to a connecting bushing, the connecting bushing being integral with an 20 end of a connection rod.

The end of the second arm may be engageable with a spherically jointed housing situated in the connecting bushing to form a coupling. The coupling between the spherically 6 jointed housing and the end of the second arm is a free coupling permitting the rotation of the end of the second arm around a centre of the spherically jointed housing.

In another preferred embodiment of the invention the first plunger is integral with a push rod which rests on the first arm of the manoeuvring elements, the push rod reducing the dimensions of the first plunger to reduce its weight.

There may be provided sealing means which co-operate with the thrusting mechanism to prevent an unchecked flow of fuel towards the chamber through the second channel.

In yet another possible embodiment of the present invention there is provided a self-compensating and electrically heated reducer for compressed gas or l.p.g. comprising: a supporting body; a chamber connected to an entrance and an outlet; a diaphragm which at each variation of the internal pressure of the chamber owing to the different amounts of gas fed controls a closing mechanism of an opening inlet to keep the pressure inside the chamber constant between the entrance, which connects with a bottle for compressed fuels or 1.p.g., and the outlet, which connects with an internal combustion engine, in response to the vacuum 15 caused by the engine; the opening inlet being situated at the end of a first channel placed in the body between the entrance and the chamber, and the closing mechanism for the opening inlet controlling the flow rate of fuel, owing to the action of manoeuvring elements kinematically connected to the diaphragm, on the closing mechanism controlling the pressure of the fuel coming from the bottle; a thrusting mechanism which acts on at least one of the 20 manoeuvring elements to cancel the resultant or the momentum which results from the action of the pressure of the fuel on the manoeuvring elements wherein the diaphragm is connected with a first arm of the manoeuvring lever by means of a connection rod which engages with a second arm of the lever, and the closing mechanism is situated at the end of a first plunger 7 which acts on the second arm by means of the thrusting action brought about by the pressure of the fuel in the first channel, a second channel, which receives the thrusting mechanism, being disposed between the entrance and the chamber; the lever having a third arm opposite the first arm with reference to the pivot on which it pivots; the thrusting mechanism urging on the third arm to negate the momentum of the first plunger's thrust with a thrust due to the pressure of the fuel in thre second channel.

In a particularly preferred embodiment, electrical resistors connected with the feeding system in the engine are placed in thermic contact with the walls of the body.

Advantageously the electrical resistors are placed near the opening inlet.

Preferably the resistors present a resistivity which varies in inverse proportion to the temperature.

Further advantages, details and salient features of the invention will be outlined in the following description of a preferred embodiment of the reducer as in the present invention, with reference to the accompanying Figure, which is a vertical section view of a reducer as in S 15 the present invention.

The reducer illustrated in the Figure forms a part of a feeding system of an internal combustion engine fed by compressed gases or comprising known structures and components, which are not illustrated.

The reducer as illustrated consists of a supporting body 1 which has an entrance 2 connected with a bottle (not shown) and containing a compressed gas like methane, acetylene, hydrogen or l.p.g.

The entrance or inlet 2 is connected to a first rectilinear channel 3 having a first diameter 0I, and a second channel 4 having a second diameter 02 which is greater than the 8 first diameter (DI, channels 3 and 4 being cut in the body 1. Channel 3 leads into a chamber by means of an inlet opening 6 controlled by a closing mechanism 7. The closing mechanism 7 opens and closes the inlet opening 6 according to the axial movements of a first plunger 8, which moves within a guiding perforation 9 coaxial to the first channel 3. The plunger 8 is integral with a push rod 10 which rests on a first arm 11 of a manoeuvring lever 12 pivoting in a pivot 13, the pivot 13 being supported by body 1.

The function of the push rod 10 is to reduce the dimensions of the plunger 8 and to reduce its weight so as to reduce its inertia.

In use, the plunger 8 is free to move in direction F 4 owing to the thrust of the pressure of the fuel which is emitted from the inlet opening 6 when the lever turns in a clockwise direction. The piston moves in the direction F 3 of the lever 12, which rotates in an anticlockwise direction to close the inlet opening 6 by means of the closing mechanism 7, the lever 12 maintaining the cdsing position of plunger 8 in this position.

A second arm 14 of the lever 12 presents an end 15 which is kinematically connected 15 to a connecting bushing 16 integral with an end 17 of a manoeuvring rod 18. The manoeuvring rod 18 is connected to a diaphragm 19 by means of two rigid plates 20 and 21.

A spring 25 presses on plate In the embodiment illustrated in the Figure, the end 15 is introduced into a spherically jointed housing 22 situated in the bushing 16 to transmit the movements of the latter with 20 lever 12. The coupling between the housing 22 and end 15 is a free coupling permitting the rotation of end 15 around the centre of the housing 22.

o• 9ooo* 9 The manoeuvring rod 18 moves with the diaphragm 19 in the two directions indicated by the arrows F, and F 2 which, respectively, permit the diaphragm 19 to increase and reduce the volume of the chamber A channel 23 connects the chamber 5 to outlet 24 which, in its turn, is connected to other components of the feeding system (not shown).

The actions which operate on lever 12 are due both to the movements of the diaphragm 19 and to the thrust resulting from the pressure of the fuel on the closing mechanism 7. The first actions are controlled by the chaacteristics of the membrane 19 and by the preloading of the adjustment of the spring 25. The actions are therefore capable of being controlled.

The actions due to the thrust of pressure of the fuel cannot be controlled, and their intensity varies from several newtons to zero according to whether the bottle is full or empty.

It is obvious that a thrust of several N. would have an adverse effect on the precise adiustment by the diaphragm 19 of the flow rate. In fact, when the diaphragm moves in direction F1, the 15 closure of the opening inlet 6 by the closing mechanism 7 is prevented by the thrust of pressure of the fuel on the same element 7. When the diaphragm 19 moves in directs.) F 2 the opening of the inlet opening 6 by the closing mechanism 7 is facilitated by the same pressure.

These actions caused by the pressure of the fuel are uncontrollable and vary from an intensity which approximates closely to the intensity of the action of the diaphragm 19. When the bottle is full and during the opening of the inlet opening 6, these actions are added to the actions of diaphragm 19. When the bottle is empty, the same actions are zero.

To correct these disadvantages, a second plunger 26 is housed in the channel 4 which moves in a part 27 of the channel 4 in the directions F, and F 4 Since the part 27 is parallel with the channel 3, the directions F 3 and F 4 of the mov :ts of the plunger 26 are parallel with the direction of the movements of the first plunger 8. In addition, an end 28 of the plunger 26 is in contact with the end 29 of a pusher 30 fitted with a sliding housing in a cylindrical cavity 31 coaxial to part 27 of channel 4. The movements of the pusher 30 occur in the directions F 3 and F 4 A second end 32 of the pusher 30 rests on a third arm 33 of the lever 12, arm 33 being opposite the first arm 11 in relation to pivot 13.

The pusher 30 placed between the plunger 26 and the arm 33 serves to articulate the thrusting means formed by the piston and the pusher Sealing means to prevent an unchecked flow of fuel towards the chamber 5 through the channel 4 and part 27 have been provided. These consist of an elastic ring 34 and a metallic ring 35, respectively, being housed in a cavity 36, in which the piston 26 moves, and in which part 27 of channel 4 terminates.

As may be seen from the Figure, it is evident that the lever 12 receives two thrusts owing to the pressure of the fuel in channels 3 and 4. The first thrust has the effect of rotating 15 the lever 12 in a clockwise direction. The second thrust rotates lever 12 in an anti-clockwise direction, so as to cancel the movement due to the first thrust and to maintain the lever 12 under the control of the diaphragm 19.

Since the second piston 26 encounters friction owing to the presence of the blocking devices 34 and 35, an advantage of a preferred embodiment is that the diameter 02 of channels 20 4 and 27 should be greater than the diameter D, of channel 3 in order to negate the momentum of the thrusts caused by the pressure of the fuel on lever 12.

As shown in the figure, the walls 38 which enclose the area of body 1 next to the opening 6 present a cavity which houses the electrical resistors 37 connected with the 11 electrically operated feeding system of the engine. These resistors are placed in thermic contact with the walls 38 to heat the fuel which, when flowing out from the opening inlet 6, expands and cools. They are electrically isolated from the body 1 by means of isolators (not shown).

The resistors 27 have the advantage of being type the resistivity of which varies according to the temperature to which they are subjected, the purpose being to give quantities of heat for units of time which decrease in duration as the temperature rises. In the heating phases, when the heat which is required to heat the fuel as it emerges in an expanded form from the inlet is greater, the resistivity of the resistors 37 diminishes, and the amount of heat given per unit of time by the resistors is greater. In the working phases of the engine at a stabilised temperature, when the amount of heat required to he-t the fuel is generally less, the resistivity of the resistors 37 increases so that they can give smaller amounts of heat per each unit of time. Since, generally speaking, heat absorbed by the fuel which passes through the inlet opening 6 depends on the flow rate, the resistors maintain the temperature of the fuel 15 constant, changing their electrical resistivity according to the temperature, so as to give greater amounts of heat per unit of time in direct proportion to the flow of the fuel. In this way the temperature of the fuel at the outlet of the reducer is virtually constant during any working condition and whatever the thermic state of the engine.

:From the above information and illustration, it may be concluded that a 20 self-compensating reducer has been constructed for compressed gases or in which the adjustment of the mass flow of the fuel during the different working states of the engine does S. not depend on the pressure and temperature of the fuel in the bottle, nor on the thermic state of the engine. The idling speed of the engine, the consumption of fuel and the emission of 12 polluting gases can therefore be accurately controlled, whatever the working state of the engine. The resistors 37 provide the walls of the body 1 in the proximity of the inlet opening 6 with amounts of heat which are sufficient for the instantaneous flow of the fuel. They keep the fuel at a constant temperature downstream from the inlet opening 6, and cooperate with the diaphragm to establish the correct mass flow of the fuel to the engine.

*0«o o e t *S *o *O oo e 13 1. A self-compensating and electrically heated reducer for a feeding system of an internal combustion engine fed by a compressed fuel such as l.p.g. comprising: a supporting body; a chamber in the supporting body which is connected by a first channel in the supporting body to an inlet which is able to be connected to a container of the compressed fuel, whereby the chamber is fed with the compressed fuel, the chamber being also connected to an outlet which is able to be connected via other components of the feeding system to the internal combustion engine; a closing mechanism which opens and closes an inlet opening of the first channel which 10 opens onto the chamber, the closing mechanism thereby controlling rate of flow of fuel through the opening inlet to the chamber; a diaphragm; manoeuvring elements mechanically connecting the diaphragm with the closing mechanism whereby at each variation of internal pressure in the chamber in response to a vacuum caused by the 15 internal combustion engine, the diaphragm acts via the manoeuvring elements on the closing mechanism to vary the rate of flow of fuel to the chamber to keep the internal pressure in the chamber substantially constant; a first thrusting mechanism which acts on at least one of the manoeuvring elements and which uses pressure of the compressed fuel to provide a cancelling thrust which cancels a thrust transmitted to the manoeuvring elements by the closing mechanism and resulting from pressure applied on the closing mechanism by fuel flowing through the inlet opening of the first channel; and electrical resistors, connectable to other elements of the feeding system, placed in thermic contact with walls of the body near the inlet opening of the first channel.

Claims

2. A reducer as claimed in claim 1 wherein: the manoeuvring elements comprise a first manoeuvring lever mounted in the supporting body for rotational movement about a pivot point and having first, second and third arms, the second arm being mechanically connected to the diaphragm so that the diaphragm can rotate the first manoeuvring lever; the closing mechanism for the inlet opening of the first channel comprises a second thrusting mechanism which has a first plunger for opening and closing the inlet opening of the first channel, the first plunger being engaged with one end of a first push rod which at. the other end thereof 10 engages the first arm of the manoeuvring lever, whereby pressure applied on the first plunger by the fuel passing through the inlet opening results in a thrust on the first arm of the manoeuvring lever which acts on the first arm of the manoeuvring lever in a first direction; l a second channel in the supporting body connects the inlet to the chamber; and the first thrusting mechanism comprises a second plunger located in the second channel, the 15 second plunger being engaged with one end of a second push rod which at the other end engages the third arm of the manoeuvring lever, whereby pressure applied on the second plunger by fuel in the second channel results in the cancelling thrust which is applied on the third arm of the manoeuvring lever and which acts to rotate the manoeuvring lever in a second sense opposite to the first sense and thereby negates the thrust on the first arm of the manoeuvring level.
3. A reducer as claimed in claim 1 or claim 2, wherein the electrical resistors present a resistivity which varies in inverse proportion to the temperature.
4. A reducer as claimed in claim 2 or claim 3 wherein the first channel has a first cross-sectional area and the second channel has a second larger cross-sectional area. A reducer as claimed in any one of claims 2 to 4 wherein the first channel is rectilinear, and the second channel has a rectilinear part parallel with the first channel.
6. A reducer as claimed in any one of claims 2 to 5 wherein the second arm of the manoeuvring lever includes an end which is mechanically connected to a connecting bushing, the connecting bushing being integral with an end of a connection rod which is connected to move with the diaphragm.
7. A reducer as claimed in claim 6, wherein the end of the second arm of the manoeuvring lever is engaged with a spherically jointed housing situated in the connecting bushing to form a coupling.
8. A reducer as claimed in claim 7, wbhr-in the coupling between the spherically jointed housing and the end of the second arm is a free coupling permitting the rotation of the end of the 06: 10 second arm around a centre of the spherically jointed housing.
9. A self-compensating and electrically heated reducer substantially as herein described with reference to the accompanying drawings. Dated this 31st day of October 1996 PATENT ATTORNEY SERVICES Attorneys for The Applicant o* PAETATRNYSRIE 15Atrny*o Th*plcn